Telephone-exchange.



' H. P. CLAUSEN.

TELEPHONE EXCHANGE.

APPLICATlON FILED SEPT. 14, 19l 7.

Patent-ed Apr. 16, 1918.

, UNITED STATES PATENT OFFICE.,

HENRY PETER CLAUSEN, or momv'r was. NEW YORK, Assrenon. T0 WESTERN ELECTRIC COMPANY, INCOBTORATED, OF NEW YORK, N. Y., A CORPORATION NEW YORK.

TELEPHONE-EXCHANGE.

Applicationfiled September 14, 1917. Serial No. 191,872.

To all whomz't may concern:-

Be it known that I, HENRY P. GLAusnN, a

citizen of the. United States, residing at a full, clear, concise, and exact descriptlon.

This invention relates to telephone exchanges and more particularly to the arrangement of substation circuits in connection with which impulse sending devices are used for transmitting impulses over the subscribers line to cause the selective actuation of the central oificeswitching mechanism.

As a precaution against the iznproper operation of the selective switches, substation circuits have heretofore been arranged so that a subscriber in initiating a call causes a closure of the line circuit by the first movement of the impulse transmitter from its normal position. Since, by such a rovision, the: completion of the line circuit to start the finder or equivalent "switch does not depend upon the removal of the receiver from its switchhook, a suflicient period of .time is insured for said swit'ch'to performits complete operation before the first series of impulses is transmitted. This of course is an advantageous feature where the normal operating conditions are considered. However, the placing of the subscribers line circuit under the control of thecalling 'de-. vice independently of the receiver switchhook gives rise to the possibility ofcertain;

undesirable conditions. If, for example, the

' subscribers calling devices is inadvertentl actuated, a finder or equivalent swltc moves into connection with the line and extends the same'to a succeeding selective switch. Then when impulses are subsequently sent over the linesaid selective switch is actuated to seize an idle trunk and render the same busy to other switches until the callin its normal positlon.

The object of the present invention is to provide a substation circuit arrangement of the above character, wherein the first movement of the impulse sender from its normal position establishes a closure of the line circuit independently of the switchhook position', and also to provide means whereby tend said line to an idle selector;

device is again restored to Specification of Letters Patent; te t A 1 1918,, v

the return or line interrupting movement of 85 the sender is only. effective to transmit impulses over' 'the. ine when said switchhook 1s released by the removal of the receiver. I

cally illustrates the circuits and mechanism of a subscribers substation embodyin the featuresof thesaid invention, and Flg. 2 shows an alternative arrangement of the circuits and devices illustrated in Fig. 1.

Referring to Fig. 1 the dial of a calling transmitteris represented at 1, and is providedwith a series of finger-holds 2 by means of which the transmitter is manipulated to transmit any desired number of impulses over the/line conductors 3 "and 4. An impulse wheel 5 has a series of circuit interrupting teeth 6 arranged to cooperate with the lever 7, and is also provided with a finger 8. Finger 8 is arranged to retain 'the off-normal contacts 9 and 10 open while for a purpose later to be described.

Assume that the subscriber in initiating a call removes his receiver 11 from the switchhook 12 before he commences to operate the dial 1. A circuit is thereby closed for line conductors 3 and 4 as follows: conductor 3,

receiver 11, transmitter 13, contact, 14, contact lever 15, interrupting contacts 16 and 17, to line conductor 4. The closure of this circuit sets a line finder in operation in the well known manner to ex- The subscriber now rotates the dial 1 in a clockwise direction through. the pro'per distance. When released the impulse wheel 5, returning to normal under the influence of spring 18, causesteeth 6 to engage lever 7 thereby opening and closing theinterrupter springs 16 and 17 a number of times corresponding to the particular setting of the dial 1. Should, however, the subscriber fail to remove his receiver from the hook to complete the above traced circuit until after the dial 1 has been partially rotated to its set position, another circuit will be closed between 0on ductors 3 and 4 to give the line finder suffition. Such circuit is completed at the &-

. 7 normal contacts -9. and 10 at the first rotaoperates the calling tion of the dial, and may be traced from conductor 3, conductor 19 contacts 10 and 9, contacts 20 and 21, conductor 22, to conductor 4a. The subscriber having, ,as assumed, removed his receiver 11 before the sender reaches its-full forward position, said sender upon its return to normal interrupts the line circuit as already described.

It will be observed that the previously traced bridge acrossline 3, 4 comprising conductor 19, contacts 10, 9, contacts 20, 21

and conductor 22 does not include the interrupter contacts 16, 17. When receiver 11 is removed from the hook 12, this bridge is opened by contact lever 15 pressing contact out of engagement with contact 21, and a new bridge is closed by the engagement of contacts 15 and 20 to include the interrupter contacts 16 and 17 in the circuit: of the line. This latter circuit is traceable from conductor 3, conductor 19, contacts 10 and 9, contacts 20 and 15, interrupter contacts 16 and 17 to conductor a. I

- While the sender is returning to normal the successive interruptions by contacts 16 and 17 do not produce a disagreeable click in the receiver since the same is shunted out by the circuit just traced. Upon the return of dial 1 to its normal position, jfinger 8 again moves contact 9 out ofengagement with contact 10.

Assume now that the subscriber, with no intention of initiatin a call, accidentally ial 1. As above explained this will result in the operation of a finder or other preliminary switch. But in however, receiver 11 is removed from hook this case, since the receiver 11 remains on the hook 12, the opening and closing of interrupter contacts 16 and 17 by the return movement of the sender is not efi'ective to send impulses over-the line. I

Referring to Fig. 2 the removal of receiver 11, from switchhook 12 closes a circuit for the line as follows: line conductor 3', receiver 11, transmitter 13, contact .14, switchhook 12 interrupter contacts 16 and 17, to line conductor' l. If the receiver is left on' its hook and the dial 1 is operated, the first movement thereof from its normal. position closes a circuit for the subscribers line, traceable as follows conductors 3 and 19, ofi-normal contacts 10 and 9, switchhook 12, contact 23, conductor 24:, to line conductor 4. It will be seen that this bridge across conductors 3 and 4, as in the case of Fig. 1, does not include the interrupting contacts 16 and 17 and therefore, the return rotation of dial 1, While efi'ective to open and close said contacts, does not result in the transmission of impulses over the line. When,

sent over the line circuit.

- sendin incense tact 23.. ln'this case the operation of interrupter contacts 16 and 17 by the return of dial 1 causesa series of impulses to be This circuit is traceable as follows: conductors 3 and 19,

off-normal contacts 10 and 9, interrupter contacts 16 and 17 to conductor 4,

What is claimed is: 1. A telephone substation having in combination, a subscribers line, a switchhook,-

a sending device operative tosuccessively interrupt said line, means foriclosing said line by the first movement ofsaid device from its normal position, and mean's controlled bythe switchhook for-.maintaining said line closed during the operationof the sending device. I

2. A telephone substationhaving in combination, a normally open line circuit, a switchhook, a sending. device arranged to successively interrupt said line circuit, contacts operated by said sending device when moved from its normal position for closing said circuit, and meanscontrolled b said switchhook for rendering the operation of said sending device inefiective.

3. A telephone substation having in combination, a line, a sending device, a switchhook, a' circuit including said line in series, means arranged to close said circuit when said device is moved from its normal position, a second circuit including said line in series, interrupter contacts therein arranged to be operated by said sendin device, and means controlled by said switch ook for renv derin eifective either of said circuits.

4. telephone substation having in combination, a line, a switchhook,,a sendin device, a set of contacts arranged to bee osed arranged to be actuated by the return movement of said device, and means controlled by the switchhook for connecting'said line in. series with either of said sets of contacts. 5. Atelephone substation havin in com.- bination, a line, a movable switc device, 'a set of ofi'-normal contacts closed y the first movement of said device, a set of interrupter contacts arranged tobe actuated by the return movement of said device, and means for closing said line in series with saidofi-normal contacts while the switchhook is in one position and for'closing' 1120 said line in series with both of said sets of contacts while the switchhook is inanother position.

6. A telephone substation having in comook, a

bination, a line, a receiver and its switchhook associated with said line, a sending deyice, cpntacts actuated thereby for interrupt mg said line, a normally open bridge across sa1d .line arranged in shunt relation. to the.

interrupter contacts, ofi-normal contacts in'- bridge also serving to shunt the receiver dursaid bridge for closing the same when said ing the operation of said sending device. device is moved from its normal position, In Witness whereof, I hereunto-subscribe and means controlled by said switchhook for my namethis 8th day of September A. D., 10

altering said bridge from shunt to series 1917. relation to said interrupter contacts, said HENBY PETER GLAUSEN. 

